Brief Summary of Minutes of Annual Meeting

The Multi-state project S1018 Irrigation management for humid and sub humid areas has four objectives: 1. Improve automation, control, and distribution technology to increase irrigation efficiency. 2. Improve irrigation scheduling methods and the knowledge/application base associated with crop coefficients, reference evapotranspiration predictions, precipitation forecasting, and field-based sensor systems as they relate to plant water use. 3. Enhance water supplies and reduce water quality impacts of irrigation management where rainfall is an important component of the water supply issue; and 4. Enhance the transfer of irrigation technologies and management alternatives emphasizing economic and environmental benefits. These four objectives of the Multistate Project overall will lead to increased irrigation need determination, effectiveness, availability and education. Irrigation management includes many critical steps: (a) determining the need for irrigation effectively, (b) determining the amount of irrigation correctly, (c) timing the irrigation precisely, and (d) managing field and equipment variability adequately. Summary of a large number of Mississippi cotton irrigation tests demonstrated irrigation often did not increase yields and sometimes decreased yields. The Mississippi cotton field irrigation experimentation highlights the value and need for field tests of irrigation management technology as a valuable, if highly underutilized tool overall, to assess the efficacy of irrigation management strategies and methods. Consequently, irrigation application, soil water sensing, determination and application technology continue to develop. Considerable collaboration in soil water determination and distribution including sensors and application technology is ongoing among scientists working on cotton in Mississippi (both state and ARS), Missouri, Arkansas, Tennessee, Alabama, Louisiana, Georgia and South Carolina. This work is greatly facilitated and enhanced by the Multistate Project S1018. The weighing lysimeter research and facilities in Louisiana, Mississippi, Alabama and South Carolina (Clemson University) provide valuable objective measurements of cotton crop water use based on a range of environmental experimental conditions. Water supply conservation and enhancement is obviously critical to effective irrigation strategies. Georgia, Florida, Alabama and Louisiana, in cooperation with the state agencies and NRCS, are effectively evaluating their water supply resources. Irrigation distribution research is ongoing in Delaware, South Carolina/Clemson University, Mississippi and North Carolina In Delaware, tests and assessments of growers aboveground irrigation systems is supported by the NRCS and is being extended into Maryland. The legal mandate in Georgia to include agricultural well flow meters and precise mapping of above- and below-ground irrigation resources will be useful to all states with irrigation utilization for agricultural crop production. Finally, effective educational outreach of such knowledge is greatly needed for producers. Educational and extension activities are critical to exploiting the knowledge gained from the research efforts. Georgia, Florida, Arkansas, Louisiana, Mississippi and Louisiana are actively collaborating in various educational efforts with other states participating less formally. Collaborative efforts are extensive among scientists in the Multistate project S1018. The Multistate project S1018 Irrigation management for humid and sub humid areas members have provided significant advances in all four objectives of the project. The even more critical fact is that, through collaboration among the project members, the value of such efforts is multiplied greatly. 1)Improved automation, control, and distribution technology to increase irrigation efficiency. In Florida, real-time measurements are essential in automated systems with feedback control based on soil water content. Such systems, particularly those targeted at high value crops, continue being developed and tested in the region. In Florida, disk rain sensors were tested for improving irrigation urban landscape irrigation. In South Carolina, a pair of custom software was developed to support Clemson Lateral Irrigation System. The first one, Field Configuration Utility, collects the field information, including the length and width of the field, its GPS coordinates, number of irrigation control sections and zones. You can also graphically prescribe a site-specific irrigation depth map. The other software, Clemson Lateral Irrigation Control (CLIC), takes this map and actually controls the irrigation system. Using these two programs, fields with any size and configuration can be fitted with a Clemson Lateral Irrigation Control System with up to 23 control zones. In the U.S. Virgin Islands, research to optimize shade levels and irrigation for Anthurium and baby-arugula were conducted. For Anthurium, daily micro-sprinkler irrigation of 2.2 and 1.1 mm were optimal for 60% and 80%shade, respectively. Optimal shade level for baby arugula was 30%, which reduced water requirement by 20%. Yield of fresh green and dry biomass was maintained improving water use efficiency and productivity. In rice, research has been conducted in Mississippi, Louisiana and Arkansas on the use of multiple inlet irrigation technology. In Mississippi the use of intermittent, multiple inlet irrigation was researched. In North Carolina, a research project to evaluate commercially available irrigation technologies was initiated in fall 2006. Forty plots with irrigation system, sensors and sod were installed. Data collection started in April 2007 comparing an ET controller, two soil-moisture feedback systems and standard irrigation clock with rain switches. Three irrigation frequencies are also being evaluated. In Mississippi, inexpensive sensors, designed to sense continuously and accurately soil water tension relative to irrigation, are being developed and tested. In Louisiana, assessments were made of "spin ditch" spacing, depth and depth to distribute water between furrows in zero grade (level basin) rice fields. Also in Louisiana the evaluation of EASY pans for estimating irrigation water needs was conducted. Impact Disk Rain sensors saved more than 1/3 water use compared with time based irrigation schedule with no sensor for residential landscapes in Florida. Water use was reduced by 25 percent over three years with multiple inlet irrigation rice production combined with intermittent rice irrigation or with multiple inlet irrigation alone in another test. Variable rate irrigation (VRI) technology is a relatively new concept in agriculture which applies irrigation water to match the needs of individual management zones within a field. It can lead to substantial water conservation while increasing crop yields. VRI technology is not commercially available for lateral irrigation systems. The new Clemson software and controller will make the VRI lateral system more efficient for researchers and also growers. Automation of sensing/irrigation will allow timely irrigation decisions increasing yield and crop water use in cotton. 2. Improve irrigation scheduling methods and the knowledge/application base associated with crop coefficients, reference evapotranspiration predictions, precipitation forecasting, and field-based sensor systems as they relate to plant water use. Irrigation scheduling in humid regions is a challenge for producers. Tests were conducted in 2006 to determine the optimum irrigation scheduling method for cotton utilizing site-specific irrigation management. A variable rate linear-move sprinkler irrigation system was used to compare five different irrigation-scheduling methods. The soil electrical conductivity (EC) data was used to divide the test field into five management zones. The following treatments were applied at random to the plots of each zone: irrigation scheduling based on 1) soil moisture sensors; 2) pan evaporation data and a crop coefficient; 3) tensiometers; 4) reference evapotranspiration model (Jensen-Haise); and 5) no irrigation. The soil moisture-based treatments (tensiometer and TDT sensors) significantly increased seed cotton yields compare to the ET-based treatments (pan & NOAA). All irrigated plots yielded significantly higher then the non-irrigated plots. Moisture-based treatments applied significantly more water than ET-based treatment. The irrigation depth applied was a significant factor affecting the seed cotton yields. It was found that soil moisture sensors and tensiometers can be used successfully for site-specific irrigation scheduling in production fields. However, since the evaporation pan and ET models provide irrigation depths independent of the soil variations, it is not suitable for site-specific irrigation management. In order to move this innovative technology into practical use among growers, in 2006, three VRI systems were installed on farmers' center pivots in SC. In Mississippi, accurate crop coefficient functions for irrigation scheduling of cotton are being developed in conjunction with lysimeter use to monitor cotton crop water use. Also in Mississippi, the accurate determination of crop water potential is being researched. In Alabama, cotton yield responses to various sprinkler irrigation scheduling techniques were tested. These irrigation schedules were guided by remote transmission of soil volumetric water contents at 3 depths. These will be followed by yield monitoring techniques to measure scheduling efficacy. Fertigation study to evaluate N and K liquid fertilizer injected closer to the beginning off the season resulted in highest yield In Arkansas, the Arkansas Irrigation Scheduler has been developed and utilized over several years. The product is utilized in several states including Louisiana and Missouri. Also, in Arkansas a computer program for scheduling the drainage of rice fields based on soil water holding capacity and timing of stages of development was field-tested in 2005 and 2006. The results indicate no reduction in yield or quality compared to conventional draining schedules. The testing is continuing in 2007. Research on irrigation termination timing on soybean has resulted in recommendations being fine tuned based on maturity group and growth stage. Research on affects of different irrigation termination times for cotton based on heat unit accumulation and crop growth stage. Work is focused on providing irrigation termination recommendations in a format similar to insect treatment termination recommendations. A study in Delaware was continued in 2006 in which Multi-sensor Capacitance Probes (MCPs) are used to measure soil water content (SWC) and dynamics under plastic-mulched drip irrigation. Near-continuous measurements of SWC were made at 10, 20, 30, 50 and 70 cm depth under watermelon irrigated at low, medium and high rates. The measurements were made in the center of the mulched bed, halfway towards the edge of the bed, and outside the bed in bare soil. The measured SWC dynamics illustrate the complexity of mulched drip irrigation in a humid climate. The data also provide information on root distribution with depth, location and irrigation amount through water observations of water uptake by the roots. Impact High production costs and low cotton prices make it more important for our growers to maximize yields. There is no published information on optimum irrigation scheduling method in cotton production for site-specific irrigation management. Nor is there a standard procedure to schedule irrigation based on the fields spatial variability. Innovative irrigation practices that use the latest technology for irrigation scheduling will result in high water use efficiency and higher crop yields. Development of accurate cotton crop coefficients for Mississippi Delta will improve irrigation scheduling. Accurate simple methods of measuring crop water potential will improve timing and accuracy or irrigation application saving producers time and money. Use of the rice growth staging program to guide drainage of rice fields for harvested in a minimum savings of $4 to $18 per acre in pumping costs. The Arkansas Irrigation Scheduler program is used extensively in Arkansas and also in other states. It is used effectively with cooperating growers for timing of irrigation in cotton, corn, milo and soybean. Later irrigations based on the fine tuning of soybean irrigation termination based on Maturity group and growth stage have been show in increase yields by up to 10 bushels/acre under some conditions have shown to increase yields by up to 10 bu/ac. Although drip irrigation can be very efficient, it can be difficult to manage and so may result in excess water use and leaching under the drip line, particularly in sandy soils. This research should result in improved guidelines for drip irrigation in a humid climate that take into account the potential contribution that rain can make to crop water use, depending on the amount, frequency and intensity of the rain as well as irrigation management 3. Enhance water supplies and reduce water quality impacts of irrigation management where rainfall is primary component of the water supply issue In the U.S. Virgin Islands, rainfall and evaporation under two shade levels were monitored to develop a water budget for a rain-based water-sustainable production system. Rainfall in 2006 was deficient 5 and 3 months for 60% and 80% shade, respectively. Therefore, rain collectors and storage would be necessary to satisfy water requirements. In North Carolina, a subsurface irrigation system was installed at a research station to evaluate agronomic and environmental performance compared with a traditional spray irrigation system in the application of anaerobic swine effluent. Off stream storage reservoir are being investigated for enhancing water supplies for irrigation in Alabama. By applying the rice growth staging/soil water reservoir model will result in unnecessary irrigation and reducing irrigation without reducing yield and quality will lead to increased water supplies in the future. . A 3-year program for in-field evaluations of growers center-pivot systems funded by NRCS in Delaware was completed in 2006. In 2006 the program was extended to Maryland, and has received a one-year renewal in Delaware for 2007. Two radial lines of specially constructed catch cans (rain gauges) are used under each pivot, following the standard published by the American Society of Agricultural and Biological Engineers. Growers receive a chart of their systems performance showing the average irrigation amount, the coefficient of uniformity (CU) and the variation in application along the system, along with a comparison of measured and design irrigation amounts over a range of timer settings. If the measured average irrigation deviates significantly from the chart supplied with the system, (or if the chart is not available) a revised chart based on the measured irrigation is also provided. To date, over 150 center pivots have been evaluated, representing a significant portion of the irrigated area in Delaware. Georgia studies have been initiated to determine the storage and yield potential for on-farm ponds and for larger reservoirs. Currently most farm ponds are in the Tifton and Vidalia uplands physiographic provinces where heavy clay sub-soils and parent material separate pond from underlying aquifers. Most of these ponds are small, averaging 2.6 acres, but more than 68,000 ponds have been identified and mapped in the agricultural region of Georgia. Agricultural permits indicate that in excess of 8,000 withdrawal permits have been issued for surface water withdrawals. Based on recent mapping efforts 40 to 50% of them are active. Not all withdrawals from ponds require permitting. Most ponds rely upon rainfall runoff, but a smaller number intercept perennial streams and springs. Of ponds used for irrigation approximately 20% are refilled from groundwater sources, exposing groundwater to evaporation before the water can be pumped to the irrigation field. The cumulative impact of their function on water flow is one of the study objectives. Cooperative work in Arkansas, Mississippi (ARS) and Missouri (ARS) on development and testing of wireless water depth sensors that are more economical than what is currently available in the market. A CSP (Conservation Security Program) project with NRCS (Natural Resource Conservation Service) is being implemented on a farm in NE Arkansas for the evaluation of the sensors. On-farm studies on BMP (Best Management Practice) effectiveness in reducing irrigation water use and runoff and for protecting the watershed has been conducted in the LAnguille River Watershed in the Arkansas delta. Impact Developing water sustainable production system in the USVI will help small-scale farmers reduce their dependence on expensive water (the most cost limiting factor for crop production in the USVI). In North Carolina, the potential impact is reduced impact of land application fields on water quality. More direct impact is the testing of the technical feasibility of such a system to land applied animal waste. By utilization of the rice growth staging/soil water drainage program, water use in the critical water use areas (such as the Arkansas Grand Prairie) water supplies are, at a minimum, spared unwarranted depletions. Accurate information on surface water resources will allow more rational management of these resources potentially increasing available water supplies without reducing aquifer levels. Affordable wireless depth sensors can be an integral part for more exact management of surface irrigation systems for water and labor savings. Results of the on-farm studies in the LAnguille River Watershed in the Arkansas delta indicate the BMPs (Best Management Practices) are effective in many cases and present economical information for growers to use in considering the installation and/or implementation of different BMPs. This information should be very applicable to many other delta watersheds, as well. 4. Enhance the transfer of irrigation technologies and management alternatives emphasizing economic and environmental benefits. Throughout the region, traditional extension continues to provide much of the information. Examples include field days and tours in Arkansas to show interested parties the irrigation technology and management being studied; the Agronomy week in Delaware with presentations, exhibits and industry business meetings targeting the full range of clientele, including traditional agriculture, organic agriculture, small farms and alternative crops, and equine interests; the analysis and summarization of irrigation survey information in Louisiana with potential coordination of results across the region and the development of a decision aid for irrigation investment. Georgia cooperators worked with the Suwannee Water Management District of Florida to bring automated water metering to the districts irrigators. A similar approach was used as part of research at 200 sites in Georgia. Georgia Soil and Water Conservation Commission is now installing flow meters on all permitted withdrawals for agricultural irrigation, estimated at 25,000 statewide, as mandated by the Georgia General Assembly and under a June 2009 deadline. One percent of all sites will have satellite-linked, continuously monitored meters. Georgia cooperators are assisting farmers with information on use of meters for managing irrigation, especially for correcting application amounts based on pumped volume and wetter area. Previously most farm systems lacked meters, and many systems have outdated pivot timer/rate curves. Georgia Cooperators, more than 30 county agents, and Albany State University collaborators are assisting the Georgia Soil and Water Conservation Commission in mapping and updating contacts for all permitted irrigation withdrawals. Wetted area, pump locations, and pump activity status are being mapped in GIS for the Upper Suwannee, Ochlocknee, and Satilla basins in Georgia. Georgia cooperators met with Alabama irrigation economists, regulators and irrigation specialists to review options for enhancing irrigation opportunities in central and southern Alabama counties that have traditionally depended upon rainfall only. Two presentations were made at the joint Georgia-Louisiana Turfgrass Association Meeting in Baton Rouge, LA. Chemigation and Principles and Landscape Irrigation Auditing. Three overhead irrigation workshops held in the Lower Suwanne River Basin with 122 row crop growers. These workshops were composed of morning discussions and afternoon field sessions. Economic analysis showed the combination of irrigation and deep tillage on cotton on a silty clay loam soil was not as economical as irrigation or deep tillage, alone. Irrigation surveys were conducted for North Missouri and the boot heel area of Missouri. A Missouri irrigation website has been developed: [http://agebb.missouri.edu/irrigate/index.htm]. Also in Missouri irrigation workshops were conducted. In Louisiana, a new irrigation investment decision aid was completed in a spreadsheet format to ensure that all the costs and revenues associated with adopting an irrigation system are adequately evaluated. This aid provides templates for alternative irrigation systems. Each template allows the user (cotton farmer) to either use the base data loaded in the template or preferably insert data that reflects their particular situation. Both technical operating data and cost data are used in the spreadsheet to develop the necessary information (cash inflows and cash outflows) for an investment analysis. The decision aid provides both a net present value (NPV) and a payback period approach to evaluating an investment decision. In addition, options are included to consider the cash flows associated with financing. Users may choose to finance all or a portion of the investment and have those cash flows considered in the investment analysis. Publication locations are in process. Also in Louisiana, annual reports of rice irrigation water use were summarized by type of land forming. This report illustrates savings generated from use of level basins (zero grade). Level basin uses for crops other than rice were demonstrated. Two level basin workshops and tours were conducted for farmers, county agents. NRCS staff and agribusiness reps with presenters from AZ, MS and AR In Mississippi ARS, educational efforts are being made on management of soil available moisture through alternative production systems. Conservation production systems can change the soil water available for plant production, and may reduce the need for supplemental irrigation. However, knowledge of how conservation tillage and cover crops impacts soil water for the heavy clay soils of the Mississippi Delta is limited. We measured changes in soil organic matter and soil moisture with conventional and reduced tillage, and with various cover crops, to determine the impact of management on soil moisture. Preliminary data indicate little differences in soil moisture for different production systems during a year of average rainfall. Both conservation and conventional production systems responded to irrigation. Also, in Mississippi ARS, educational efforts are being made on common principles and drivers of agricultural production systems. Changes external to agriculture significantly impact agricultural production. The evolution of the US agricultural production system is being driven more and more by social, political and economic realities that are external to the farm gate. In collaboration with ARS and University scientists from across the country, scientists at Stoneville are exploring these drivers of agricultural production, and principles of production. The Stoneville research team hosted the second in a series of meetings between producers and researchers to delineated drivers and preliminary principles of agricultural systems, and explored the impact of drivers on production systems in the Southeastern US. Presentations at field day, conference and scientific meetings on the results of tests on the Arkansas rice growth staging/soil water content program for draining rice fields. In Delaware, some growers and consultants are using a spreadsheet (together with web based weather and ET data) that is based on the FAO 56 irrigation scheduling spreadsheet but which can be corrected by field measurements and which presents the output in a graphical form that is easy to understand. A spreadsheet for Estimating Irrigation Pumping Cost has been developed in Arkansas and modified by Joe Henggeler in Missouri. A Fact Sheet for Estimating Irrigation Costs has also been updated. The Missouri Irrigation website provides visitors with excellent irrigation information and tools. Impact More than 7,000 permitted systems have been located or noted as inactive or even cancelled. The Georgia Environmental. Protection Division, which issues agricultural water withdrawal permits, was provided with updated contact information, accurate withdrawal locations and status for both permits and pending applications. Store more water in the soil limiting the need for supplemental irrigation and improving the economic return on investment. Roadmap of successful production principles and indicator of future research needs. Understanding and applying the rice growth staging/soil water reservoir model will increase knowledge and application of the model by growers and researchers. The Delaware programs result in system specific information that a grower can use, such as to identify problems, to correct the amount of water being applied, or simply to provide confidence that the system is performing well. Lack of such information can lead growers to apply excess irrigation in order to reduce the risk of under-irrigation. Anecdotal feedback from growers has been very positive, with demand for the service increasing. The scheduling spreadsheet has also increased grower awareness of scientific irrigation scheduling and the importance of periodic soil water measurement. Increasing energy prices have also stimulated growers to more carefully consider their irrigation management, and these programs with NRCS likely have a positive impact on irrigation water management and a reduction in the environmental impact. The pumping cost spreadsheet developed in Arkansas and modified in Missouri can be used to help growers evaluate their pumping costs and better determine their options for reducing their costs. The information in the Arkansas Fact Sheet on pumping costs should be applicable to much of the much of the agricultural areas in the Multistate Project participant states. Also in Arkansas and Mississippi, efforts with promoting MIRI (Multiple Inlet Rice Irrigation) have been significant. Additionally, the combination of MIRI and Intermittent Flooding of rice has been studied and introduced to growers.

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Precision irrigation strategies for the Alabama farmer. Poster presented at Auburn University Water Conference, Auburn, AL, June 18, 2007. Harmsen, E.W., V.H. Ramirez Builes, J.E. Gonzalez, M.D. Dukes, and X. Jia. 2006. Estimation of short-term actual crop evapotranspiration. Proceedings Caribbean Food Crops Society, July. Harrison, K. Chemigation in Georgia. B-1298. Print and web based publication. Harrison, K. Irrigation Scheduling Methods. B-974. Print and web based publication. Harrison, K. UGA EASY Pan Irrigation Scheduler: Pan Size Considerations. B-1201-A. Print and web based publication. Harrison, K. Gary Hawkins. Water Meters as a Water Management Tool. B-1296. Print and web based publication. Icerman, J., M.D. Dukes, and R. Muñoz-Carpena. 2006. 2-D water distributions under drip irrigation: measurement and modeling applications. FL ASABE paper. American Society of Agricultural Engineers, St. Joseph, MI. Femminella, K.L. M.D. Dukes. 2006. Effects of soil moisture based irrigation controllers on bell pepper yield and nitrogen leaching. FL ASABE Paper. American Society of Agricultural Engineers, St. Joseph, MI. Guerra, L.C., A. Garcia y Garcia, J.E. Hook, K.A. Harrison, D.L. Thomas, D.E. Stooksbury, and G. Hoogenboom. 2007. Irrigation water use estimates based on crop simulation models and kriging. Agric. Water Mngt. 89:199-207. Haley, M.B., M.D. Dukes, and G.L. Miller. 2006. Evaluation of sensor based residential irrigation water application. ASABE paper no. FL06-021. American Society of Agricultural Engineers, St. Joseph, MI. He, J., and M.D. Dukes. 2006. BMP development with the CERES-Maize model for sweet corn production in North Florida. ASABE paper no. FL06-011. American Society of Agricultural Engineers, St. Joseph, MI. He, J., W.D. Graham, M.D. Dukes, and J.W. Jones. 2006. Uncertainty analysis of the CERES-Maize model with the Monte Carlo method. ASABE paper no. 06-3027. 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